The present invention relates to a folding child stroller that may be converted between a ground-contacting four-wheeled stroller and a frame carrier for carrying a child on a person's back.
Collapsible or foldable baby carriages for walking have long been known and are generally described in U.S. Pat. Nos. 2,781,225; 3,873,116; and 4,072,318. These early carriages have evolved from more cumbersome, rigid carriages, as many carriages are now collapsible or foldable as to make them conveniently transported or stored.
The problems associated with known collapsible or foldable baby carriages or strollers are well known. For such strollers to be safe and permit smooth carrying of an infant, they must be secured together safely, such as with the use of bolts and nuts. Consequently, the disassembly of such strollers is required, necessitating the use of tools to break the stroller partially down to permit collapse or folding. Furthermore, many of these carriages or infant strollers, when in their collapsed or folded state, have one or two of their three dimensions actually extended to a longer length, height or width than when the strollers are erect. This extensibility or expansion of one or two dimensions, however, has been acceptable as the strollers were at least able to fit into trunks of automobiles and the like which permitted elongated folded frames.
With the resurgence of physical fitness, persons of all ages, including the parents of infants and young children, have developed great interest in all forms of physical exercise, particularly in jogging and walking at relatively high speeds. Consequently, infant jogging strollers or carriages that fold for transport or storage, while yet provide for safe, stable and secure carrying of a child at a relatively higher speed were developed. Several of these infant jogging strollers are shown in U.S. Pat. Nos. Des. 297,525; 4,934,728; 4,953,880; Des 315,885; and 5,029,891. However, these jogging strollers are also plagued with the problem of frame elongation upon collapse or folding for transportation and/or storage.
In addition to the ability to fold a jogging stroller for transport in an automobile, today's active parents demand a jogging stroller that can be folded to a compact configuration for use as a baby carrier, or frame carrier, for carrying the child on the parent's back. Such a device has the highest demands for a compact, folded configuration while at the same time providing safe, stable transport of the child in a stroller configuration while walking or jogging.
In addition, a convertible stroller/frame carrier must be convertible from the stroller configuration to the frame carrier configuration by using only one hand and without bracing the device with the feet, because parents often must hold the infant in one hand and must have both feet firmly on the ground to avoid the chance of a slip and fall while holding the infant. Additionally, the convertible stroller/frame carrier should be collapsible to a partially collapsed configuration in which the device may be mounted on the parcnt's back while still being self-supporting, as on a picnic table, and then convertible to the fully collapsed frame carrier configuration with only one hand.
Stroller/backpack configurations are known, as shown in U.S. Pat. Nos. 4,915,401; 4,586,721; 3,984,115; 4,157,837; and Des. 357,438. However, these devices do not fully meet the need for true one-handed convertibility as described above.
There is thus a need for a convertible stroller/frame carrier with true one-handed convertibility and partial collapsibility.